Aerial torpedo



July 15, 1952 Filed July 13, 1943 cf/vze/ ca/v P. W. NOSKER AERIAL TORPEDO )PAUL IK Sheets-Sheet 2 /Vo ske? July 15, 1952 P. w. NosKER 2,603,433

AERIAL ToRPEDo Filed July 15, 1943 8 Sheets-Sheet ,1

p, w.- NosKER AERIAL TORPEDO July 15, 1952 8 sheets-Sheet 3 Filed July 13 1943 Nwl July 15, 1952 P. w. NosKl-:R .2,503,433

l AERIAL ToRPEDo l Filed July 15, 1943 B sheets-sheet 4 .4 rak/veys P. W. NOSKER AERIAL TORPEDO July 15, 1952 8 Sheets-Sheet 5 Filed July 13, 1943 P404 ./Vo

July l5, 1952 y P. w. NosKr-:R 2,603,433

vAERIAL 'roRPEno Filed July 15, 1943 K :a` sheets-sheet e /Nvaw ron? P. W. NOSKER AERIAL TORPEDO July 15, 1952 8 Sheets-Sheet '7 Filed July 15, 1943 Avi/enrol? M @ys/EAP July 15, 1952 F.` w. NosKER AERIAL ToRPEno 8 Sheets-Sheet 8 Filed July l5, 1943 Patented July 15, lili-S! (Granted-under the act of March 3, 1883, as amended AprilSO, 1928; 370 0. G. 757) The invention described herein may be manufacturedand used by or for Governmentl for governmental purposes, without the paymentl to me of any royalty thereon.Y v

This invention relatesto aerial torpedoes, and among otherA obiects; aimsI to provideaselfpropelledV torpedo which is` inherently faster than any conventionalairplane, so that when properly guided it may' overtake anddestroy hostile aircraft byV detonation ofl an explosive charge.` The torpedo of my invention will; be an extraordinarily difficult targetfbecauseof its extremely high speed and small size. Another object is to provide an aerial torpedo light enough to be carried (partly disassembled if de sired) within. an airplaneof the bombardment or cargo .type and adaptedto beA launchedwhile the airplane is in flight. provide an aerial .torpedowhich hasautomatic flight-directing. devices vthat may, however, be controlled by an operator of a radio wave transmitting system. Anotherobject'isto providea flying. torpedo .which willi seek out nand .fly diirectly. to any. source. of infraredlrays) es g., the power plant. ofi an' enemy. plane), without guidance from. radio wavesorany'source other than .thatof said rays. Another object is to provide anY aerial torpedol having automatic,. radiocontrolled, and; infrared f. rayecontrolled night.-` directing devices', whereinra'di'o waves atthe Willof an operator may switchthe controls from automatic to. radio-controlled flightf or alternatively -to infrared.rayecontrolled iiight. A" further'obje'ct is to provide acontrolsystem for aerial torpedoes of the type indicatedv above which permits master controlby radio impulses,

regardless of the character'of control which is directing the flight at' the-instant mastercontroltakes over.

close to'or inr collision with theV target, or Yauto-y matically after slowing downor stopping ofthe-- power plant. `Additionallyfthe invention aims to provide practicable means `for launchingggthe torpedo from 'a' mother ship, which may'be a cargo type'airplane 'or evenavdirigibl'e. Other objects willappear inthe speciiication.

The broadideagof anaeri'a'lgtorpeda is of course oldgib'eing suggestedin suchpatentsas `the Mur.-

dock Patent;v No. l 1,303,105." and' :the vlviathews" Another object is` tov A furtherobject is to provide a reliable and sensitive radio control systemfor Another object is thefprovision radiation-thatisfinevitably associated with. the 15o Patent No. 1,411,861. L. B. Sperry in Patent No. 1,418,605 described the use of a pilotlessairplane controlled by a gyroscopic steering device, with an arrangement for automatic detonation after a certain length of time vhas elapsed from the launching. In Patenty No. 1,792,937 EI; A. Sperry disclosed an aerial torpedo wherein the direction of night may be controlled from a radio wave transmitting station throughout the entire flight (if within the limits of controlv of the station). Hammond in Patent No. 1,818,708 disclosed a pilotless glidery adapted to vbe released from the fuselage of an airplane and guideddurmg. its descent by radio control, with provisions for detonation upon contact, or after acertain time interval, or after sinking. to a certain depth in water. The prior art contains Vother suggestions for utilizing generally analogous systems on boats, .motor vehicles. bombs and thelike which are in this application referred -to in. the claims under the,k generic terml movable objects and to which this controlsystemrmay be applied.

Various systems have been proposed for locat ing airplanes in flight.' In? some of these-use is made of radiant energy' generated at and radiated from aposition occupied by an. observer with the defending forces. The conventional forms 'of' radio detection fall. into .this category, as do' `also all methods. of aircraft identification that are based upon. the reception of radiant energyV reflected by the airplanes on other ob.- jects under observation. However, all such schemes are subjectto the inherent disadvantage that they` are capable'of being` hamperedfby the hostileforces; eitherv by intentional transmission ofinterfering.' radiationor bythe use of nonconducting'structures (such as wood' or plastic types) that are relatively'poor reflectors ofelec.- tro-magnetic waves;v

In contrast `with the foregoing; I .provide apparatus whichwill receive and interpret infrared radiation emanating from airplanes, andv will .act on circuits controlling 'servoemotors inturn con'- trolling Ythe guiding devices onthe aerial' torpedo.

The* outstanding advantagefof, this method'isV that'no action; on-the part=of the'hostileairplane or lits` crew* can Aeliminate the infrared operationv and'vv cooling of' all vairplane vpower plants. Any attempt at theproduction of in'- terfering infraredradiation lon anairpianeby its crew would? servemerely-t'oincreasethe total radiation. andhencmwould-. assist," lrather lthan 'n hinder, def ending` f orcesfsuppiied. with the aerial torpedoes. Other advantages and uses of my invention are discussed following the detailed description of the preferred embodiment thereof shown in the accompanying drawings.

In said drawings,

Fig. 1 is a plan view of the aerial torpedo;

Fig. 2 is a side elevation of the same;

Fig. 3 is fragmentary front elevation of the same;

Figs. 4a and 4b together comprise a wiring diagram showing all the control circuits except the transmitting system;

Fig. 5 is a diagrammatic View in elevation of the circuit-selecting switch and servo-motor;

Fig. 6 is a detail in elevation of one ofthe circuit-selecting commutators;

Fig. 7 is a sectional View of one of the pendulcus devices used to control lbanking;

Fig. 8 is a section on line 8 8 of Fig. 7;

Fig. 9 is a diagrammatic view of one of the servo-motors and position-selecting potentiometers for controlling the elevators;

Fig. 10 is a detail in elevation of the potentiometer of Fig. 9 per se;

Fig. 11 is a sectional elevation, somewhat diagrammatic, of one of the directional radiation receivers employed to control the aerial torpedo;

Fig. 12 is a section on line I2|2 of Fig. 11;

Fig. 13 is a wiring diagram of the preferred transmitting system for radio or remote control of the torpedo;

Fig. 14 is a wiring diagram of the preferred receiving system for radio or remote control of the torpedo, omitting the detonating and infrared ray-controlled circuits which are shown in Figs. 4a. and 4b;

Fig 15 is a diagrammatic section of an airplane equipped with means for starting and launching the torpedoes, an alternate position of certain parts being shown in dotted lines;

Fig. 16 is a detail in section showing the means for locking the torpedo to the torpedo-launching mechanism; and

Fig. 1'7 is a similar view showing diagrammatically a means for starting the clock switch as the torpedo is launched.

General description of the torpedo The preferred embodiment of the invention has the general appearance of a monoplane, with a fuselage 2| having an armored pointed nose 22, Wings 23, tandem propellers 24 and 25 in dual rotation (so called contra-propellers), power plant 2B, ailerons 21, horizontal stabilizers 28, vertical fins 29, elevators 30 and rudders 3|. A gear box 32 is interposed between thel power plant and the propellers to give the desired speed reduction and to effect dual rotation, i. e., simultaneous rotation of propellers at equal speeds in opposite directions. Adjacent the armored nose 22 is a heavy explosive charge 33 which may be detonated. Additional explosive charges (not shown) may be distributed in any spaces available in the body of the torpedo. As the device is designed to be automatically destroyed in the event it fails to strike its target, hence will never land after launching, no landing gear is provided; and as it is pilotless, there is no pilotscompartmentor Cowling to increase the drag. The fuselage is designed for extreme `high speed performance and should not greatly exceed nine feet in length, with a Wing span of not more than six feet. It may be built principally of plywood or plastics or other light, strong material. The dual rotation propellers (affording the advantages of freedom from torque and gyroscopic reaction upon the body) should be of fixed pitch designed for optimum efficiency at or near the high speed of the aerial torpedo, and preferably are not over 4.0 feet in diameter, which means that the tip speed will be about 810 F. P. S., assuming a crankshaft speed of 6000 R. P. M. and a gear reduction of 2 :1. The propellers may be of laminated wood, the fuselage of plastics, wood or metal, and the wings predominantly of plastics and Wood or some other non-metallic material to permit installation and effective use of a radio receiving antenna (to be described) extending spanwise within the wings. A half wave antenna would be shorter than the wing span if a suitably high frequency of radio carrier wave were employed, and installation of such an antenna inside of the wing covering is preferred because this would obviate the drag caused by any external arrangement.

For the power plant a horizontally opposed, two cycle, 8 cylinder, marine type engine, developing at least brake horse power at sea level and 6,000 R. P. M., is preferred. However, crankshaft speeds up to 7,000 R. P. M. are feasible, as is shown in the art of two cycle marine engines built for racing. The ignition system is preferably dual and energized by a battery and completely shielded to obviate radio interference. Breaker points actuated by cams mounted on the crankshaft, as in a marine engine, may re the cylinders in proper sequence. Fuel delivery should be by an engine-driven pump, with dual carburetion, and cylinder charging by crankcase compression. Lubrication may be of the splash and spray type, and the cooling system is preferably of the liquid type with ethylene glycol coolant, circulated by an engine-driven pump through a skin radiator built into the wings (to reduce drag). All these power plant details are omitted from the drawings because they are not part of the present invention. Assuming a gross weight of the aerial torpedo armed and completely fueled, of 500 1b. (although by careful designing it may be nearer 400 lb.) the described power plant and propeller arrangement will drive the .aerial torpedo at approximately 400 M. P. H. at sea level, and the maximum rate of climb at sea level will be 3,070 ft. per min. If a 16 cylinder X type engine were employed, the brake horse power would be doubled without any significant increase in overall dimensions of the fuselageV and the speed would be raised to approximately 500 M. P. H. at sea level. The maximum rate of climb will be approximately 4,450 ft. per minute at sea level. if the weight is reduced to 400 lb. and the brake mean effective pressure equals 76.3 lb. per sq. in.

For high perforance at high altitudes some form of supercharging, such an exhaust-driven or geared blowers, may be employed, or oxygen could be fed into the induction system of the engine either from a liquied oxygen supply (heated by a heating chamber in contact with a portion of the exhaust manifold) or from some reducible compound of oxygen such as trinitrophenol (picric acid), C6H2'OH(NO2)3, which may be mixed with the fuel (high octane gasoline) at ordinary temperatures and hence would not require a separate tank or injection system. While picric acid is definitely destructive in its effects on the cyl-v inder walls etc., it is a more eilicient source of oxygen than liquied oxygen cylinders and saves space and weight, hence is preferred, especially as the the engine need not have yuseful life of more than'20` minutes (136 miles), and in the case of the 16 cylinderenglne'for speeds of 500 M. P. H., may not have a useful life of more than 10.2 minutes (85.6.mi1es). In any event, sufficient oxygen should be made available for complete combustion of the full normal fuel charge on each power stroke, and the smallest possible fraction of the power output should be sacrificed in the supercharging process. There is no engine speed control or throttle adjustment, since the engine is to be operated at high speed throughout its useful life.

It is contemplated that the aerial torpedoes of my invention usually wil be launched either from a large cargo-type airplane or from a dirigible. Special launching gear, one form of whichv is described herein, may facilitate moving the torpedoes out of the dors of an airplane or dirigible against wind resistance etc. The torpedoes may be carried partially disassembled, e. g., with wings and propellers detached, and may be assembled immediately prior to launching. Of course, the torpedoes also may be launched from the ground or from vessels at sea.

Automatic control systemv for straight flight To maintain the torpedo, once launched, in str aight, level flight, three Servo-motors are provided, motor 35 for controlling the ailerons, motor 3S for controlling the rudders and motor 3l for controlling the elevators. Details of the controls operated by these motors are shown in Figs. 4a and 4b.

`Servo-motor 35 (Fig. 4b) has a reduction gear train (not shown) for driving a control cable real (not shown) by which the unillustrated control cables for ailerons 2'! are moved in reverse directions. The arrangement may be exactly the same as the arrangement described below for controlling the elevators. To operate the ailerons automatically, there is a pendulous device it comprising a pivoted vane 'Sila oscillating between two contacts (not shown) electrically connected by leads ecb, 40e to the aileron servomotor 35. Pendulous device 40 is essentially an accelerationfresponsive reversing switch for controlling the `ailerons and hence the banking of the aerial torpedo, and it tends always to maintain a resultant force on the torpedo acting in a plane that is perpendicular to the spanwise diV rection. A lead Mld, connected with vane 40a, and a lead 30e connected with servo-motor 35, complete the circuit of said servo-motor and its reversing switch 49. The rudder or rudders are likewise operated by a cable (not shown) and are moved in opposite directions by servo-motor 36, the arrangement being the same as that for servo-motor 35 except there is no pendulous device acting responsive to changes in acceleration. Instead a gyroscopic turn controller 4| is connected by leads 42d, 12b to servo-motor 36 which operates the rudder to apply a proper correction each time any air current, etc., tends to deflect the torpedofrom a straight path. A lead 42o couples the gyroscopic turn controller 4| to a circuit-selecting switch 90 to be described.

To maintain a predetermined pitch of the longitudinal axis of the torpedo with respect to the horizon, a pendulous` device d3 is provided. This pendulous device comprises a housingv 4s (Figs. 'i and 8)., vane-e5 suspended within the housing from pivots it so as to swing through a small angle, adjustable contacts 41 between which the vane may oscillate, insulated holders 48 for the contacts, and leads v 159e., 49h, electrically connect-4 ing the contact points and vane 45 withthe re- 59 (Fig. 4b) connects the pivots 45. of-vane 45 withthe lead y'cswhich connects with the selecting switch 90. When. vane 45 touches one of the contacts lll it closes a circuit including servomotor 31 which causes that motor to start, turning a pinion 50 (Fig. 9) which meshes with a gear 5l on a countershaft 52. said countershaft being journaled in a, housing 53 adjacent the servomotor. Fixed to countershaft 52 is a pinion 56 driving a gear 55 on another countershaft 56 which extends outside housing 53. On the outer end of countershaft 56 is a control cable reel or grooved. pulley 5l over which acable 58 is passed. Cable. 5t-is attached to the elevators 3i) by means not shown to move them to change the pitch of theV longitudinal axis with respect to the horizon. When vane. 45 touches the other contact. the servo-motor 3l is reversed to move the elevators in the opposite direction. The gear train 50, 5l, 5d, 55, is merely diagrammatic to illustrate the working of the device; in actual practice the gear train, may be quite, different, involving perhaps a worm gear and a sector gear (not shown).`

Servo-motors 35 and 36 operate the ailerons and rudders respectively by mechanisms similar to the arrangement just described.

The two pendulous devices 49, t3 and the gyroscopic turn controller il are showndiagrammatically because they are not claimed per se herein and because various forms of regulating devices of this character may be used. They will operate automatically to keep the aerial torpedo on a substantially straight and level or preset climbing or diving course, once it has been launched, until other controls take overthe guidance of the torpedo.

Remote control by' operator Often it will be desired, especially inV daylight operations, to direct the course of the aerial torpedo entirely by radio Waves under the control of an operator in flight or on the ground; or where there are extensive fortiilcations with intercommunicating observation and control stations, several operators may take turnsv in controlling one or a series of the torpedoes as they ilash into and fade out of sight. An antenna 60 (Fig. 4a) is located inside the wings 23 for the reason already stated. Connected to antenna 60 is a radio receiver Gi to which four band pass iilters 62, 63, 64, $5 are connected in parallel by leads 66, 66a, Gl and 57a. Each of the band pass filters is also connected to a rectifier (which may be of copper oxide or some other type) whereby only direct current is passed on to the controlling relays for the servo-motors. The four rectiers 68, 69, l0, and 'il are each connected in parallel to a conductor i2 which is connected to a. lead 13 forming part of a separate circuit (to be described) coupled to the radio receiver.

Band pass filter 32 is connected in the detonating system which will be described hereafter. Bandpass filter 63l and its rectifier 69 are connected with a potentiometer 15 including a resister .16, said potentiometer having relatively movable contacts to cut in or cut out resistance. A relay 'Il is connected to pctentiomenter 15 and servo-motor 31. Preferably the arrangement is such that servo-motor 31 operates the movable contact of potentiometer 15, or what is the same thing, ya movable resistance coil against a stationary brush providing the contact. The potentiometer 'i5 may be as diagrammatically illustrated in Figs. 9 and Y10 where reversible motor 3l is Vshown adapted to rotate resistancecoil 'i8 mounted on an ,insulator 19 which is keyed or otherwise secured to countershaft 56. Resistance coil 18 is in contact with stationary brush 80 in brush-holder 8|. With this arrangement the total angular movement of the potentiometer coil 18 is equal to the total angular movement of the control cable reel 51. In exactly the same way, reversible servo-motor 36 for the rudder rotates the coil (not shown) of a potentiometer 82 (with resistor 82a) connected through rectifier 10 to band pass filter 64. Relay 84. exactly like relay 11 isinterposed between servo-motor 36 and DOentiometer 82. Relays 11 and 84 are each polarized and zero center, as indicated, and a wire 85 connects both relays in parallel with a lead 86 connected to the radio receiver 6| to form part of a separate coupled circuit as will be described.

As indicated above, the control system of my invention may be purely automatic to maintain straight line level flight, or straight line climbing or diving ight, or it may respond to radio signals, or it may react to infrared waves to guide the aerial torpedo toward the source of said waves. In order to switch rapidly from one control arrangement to another, a circuit-selecting switch 90 is provided and a reversible servo-motor 9| is employed to move relatively movable contacts to switch the circuits. Preferably the same servo-motor operates the relatively movable contacts of a potentiometer 92 having resistor 92a and receiving direct current impulses from rectiner 1| which is connected to band pass filter 65. A polarized relay 93 is also connected to servomotor 9| and to potentiometer 92 and by means of wire 94 said relay is connected with lead 86 extending to radio receiver 6|. The three potentiometers 15, 82 and 92 have their resistors connected in parallel with lead 13.

Referring to Figs. 4a, 5 and 6, the circuitselecting switch 90 is so interconnected with other parts of the wiring system as to control the switching from automatic to remote or radio Wave control, Yor alternatively to infrared control. Accordingly the circuit-selecting switch has two circuit-selecting commutators 99, each consisting of a circular insulating contact support |93 and three spaced contact segments |0I on the periphery of support |00. These commutators are xed upon a countershaft |02 rotated in reverse directions by servo-motor 9| acting through reduction gear train |03, |04, |05, |06, the latter being a pinion directly connected to the motorshaft |01. The coil of potentiometer 92 is also rotated by countershaft |02. |03, |09, held in insulating holders ||2, ||3 respectively are adapted to contact the potentiometer coil and commutatore 99, respectively. Leads (not shown) are connected to brushes |08, |99, I0 respectively and other leads, also omitted, are connected to the several commutator segments. Obviously there are three commutator segments |0| because there are three control circuits to be selectively activated by means of the circuit-selectingswitch, and two commutators 99 are employed, since there are positive and negative sides to each of the three circuits controlled through said switch.

Remote control is effected preferably by means of a modulated continuous radio wave carrying four single modulating frequencies in nonharmonic relationship and ofsuitable value to be passed respectively by the band pass filters. The controlling effect is obtained by varying individually the percentages of amplitude modulation Stationary brushes on the carrier wave due to each of the four modulating frequencies. The coils in potentiometers 15, 82 and 92 each have a definite position for every given percentage of modulation on the particular modulating frequency; therefore the rudders, elevators and vcircuit-selecting switch each have a definite position, and perfect control is obtainable when the parts are properly adjusted.

To clarify this action, the operation of the channel through band pass lter 65 will be described. The modulating frequency passed by filter 65 is rectified at 1| and the resulting direct current is passed through the potentiometer 92 and the resistor 92a. The polarized and zero center relay 93 isso connected as to be actuated by the potential drop between the movable contact on potentiometer 92 and the lead 12 commonA to all the rectiers. Thus any signal appearing in the output offilter 65 will tend to actuate the relay 93 in one Yparticular direction, and the relay will close in that direction if the amplitude of signal is suflicient. However, the output from the radio receiver through the coupled circuit formed by leads 13, 8,6 gives a direct potential having an amplitude that is proportional to the intensity of the energy received by the antenna, and this direct potential is applied to relay 93 in such a manner as to oppose the potential from the rectifier 1|. Itis evident, therefore, that for each setting of the potentiometer 92 there is a given percentage of modulation on the frequency of the filter 65 that will cause zero current through the relay coils and hence will create a state of electric equilibrium. If the modulating signal on the frequency of filter 65 is increased in amplitude while the carrier wave intensity remains unchanged, the relay will close in one direction to start the reversible servo-motor 9|, but if the signal from lter 65 is reduced the relay will close in the opposite direction to start motor 9| in the reverse direction. Now, as previously explained, servo-motor 9| turns a potentiometer 92 at the same time it turns the commutators 99 of the circuit-selecting switch, and the direction of the turn is such that the system tends always to seek its equilibrium position for every given amplitude of modulating signal. Thus the nal position assumed by the system can .be adjusted at will by the remote operator who is provided with the necessary transmitter controls to vary separately the modulation percentages due to each of the several modulating frequencies.

As stated above, the automatic Vcontrol system for straight ight is in operation only when the circuit-selecting switch is in the central position bridging central contacts |0|, as shown in Fig. 4a. When the circuit is closed through the contacts |0| on the right hand, the automatic control system is disconnected and the remote (radio) control system is made effective. When the circuit is closed through the contact |0| on the left, the automatic control systemv is disconnected and the automatic directing` (infrared) system is made operable.

While not mentioned heretofore, I have shown amplifiers 1, H8, ||9, |20 interposed between the band passV filters and the rectifiers. However, these amplifiers may be coupled between the rectiers andthe relays or I may employ two sets of amplifiers, one set on either side of the rectiers, if found necessary either for securingsuicientgain or for ofV the circuits.

understood Without illustration. Evidently such.

providing total isolation. These arrangements are readilyY amplifiers' would inpno way alter the character of the controlcircits, and` neither wouldY they change the final` results achieved.

Theoretically, Aof course, the described radio control systemv can be subjected to interference or blanketing by enemy action, vif we assume that the enemy is completely informed about the method of control being used andY is close enough to eifect such control. However, the system disclosed herein has a complexity and flexibility such that no enemy could interfere with it, exceptaccidentally, in the short period during which the serial torpedoes are in night. In the rst place, the carrier frequency for the remote control does not need to be the same for any tivo torpedoes, but can be set as desired immediately before launching. Thus neither the launching crew Vnor the remote Voperator wouldk necessarily know in advance the actual frequency to be used. Secondly, since the remote control is accomplished not by the presence or absence of `the radio frequency carrier wave, but rather by modulation imposed upon that carrier, the modulation frequencies used foicontrol purposes could be similarly adjusted individually and'irnmediately prior to launching. Hence even if the enemy could discover the carrier frequency beingused, it is extremely improbablethat hecould accurately measure and then reproducain a proper manner, and with necessary relative amplitudes, the several modulatingfrequencies required to effect control of the torpedo. The problem of intentional interference or blanketing is made especially diiiicult because of the f act `that thetotal flight time ofjany one torpedois less than half an hour, and` by the further vfact that `remote control need be used only intermittently and during a very small fraction o f the total flight time.

,Instead of the rectified carrier signal taken from the Outputleads 13, YSe from the radio receiver, a fth modulating frequency of constant amplitudeeOuld be impressed upon the transmitted carrier wave and rectified after reception to produce the opposing potential for sense 4 flete rniination of relay motion. This use of a fifth modulating frequency would not change the performance of the remote control portions of the circuit, but it would furnish a simple and convenientmeans of obtaining the necessary direct potential ina relatively low impedance circuit such as is often desirable for efficient relay operation. The preferred arrangement is shown in Figs, 13 and 14.

In 1 3, five signal generators 20|, 202, 253, 204, 205 are shown, Aeach of which. produces electricalirnpulses (preferably pure sine waves) o f'adjustable amplitude but of different frequency. The outputs of signal generators 213|, 202, 203; and y201|! are f edrespectively to variable attenuators 206, 201,2 08, 200, and thence through amplifiers 2 l 2|2, 2|?, and 2M respectively to a mixing circuit comprising leads 2|6, 2 |1. The output f a signal generator 205 is fed to the same mixing circuit through fixed attenuator 2|0 and amplifier 215. Instead of the amplifiers other irreversible coupling devices may be used. The combined signals emerging from the mixing circuit are carried to a mixer and modulator 2|8 and then through leads 2|9,`220` are conducted to radio transmitter 22| having the usual connections with antenna 222 and' ground 223, so that the signals may be impressed upon a radiofrequency carrier wave for. transmission in space.

Now referring to Fig'. 14, antenna 60 is coupled to a radio receiver 225 having a ground 225. This receiver is connected by leads 221, 22`to conductors 229, 230 connectingband' pass filters 23|, 232, 233, 232, and 235 in parallel, Combined signals received by the antenna, after dmodulation, are separated by the filters and are then amplified `by amplifiers 236, ,231, 230, 239 and 243 respectively. InsteadY of amplifiers other irreversible coupling devices may be used, and if desired, amplifiers may be used also on the receiving sides ofthe filters. The output of each amplifier is delivered to a rectier; hence there are five rectiers 24|, 242, 243, 2M and 255. The nrst four of these rectifiers are each directly connected to a fixed load circuit, here represented by the resistances 250, 241, 248, 249, t0 each of which a ground vwire 250 is connected. On the other hand rectifier 245 is connected to a circuit which comprises a solenoid25| and a lead 252 to which potentiometers 253, 254, 255 and 255i are coupled in parallel..

The reversible servo-motors 31, 36,91 and 35 as already explained move the Vmovable contacts of the potentiometers 253, 254, 255 and 256 respectively. Thus `Fig. 14 differs from Figs. sa and 4b where only three motor driven potentiometers are shown. Returning to Fig. 14, thes'ervomotors are shown coupled b ifdir'etio'nal, polarized, zero center relays 251, 252, 253 and 250 and are connected in parallel with a source of electric energy, e. g., battery 25|. .Shunts 262, 253, 254 and 265 connect each relay with the output side of the corresponding rectifier 22|, 242 etc., and leads 266, 261, 268 and 259 completeA the circuits through the potentiometers. The armatures (not shown), of the several relays 251, V258 etc., lwill assume thecentral or zero center position to stop the correspondingeervomotor when the, diiference of potential between the armature terminal is zero. However, any other difference of potential'A causes the relay armature to close in one direction or the other` to cause. the corresponding servofmotor torotate in one direction or the other to move `the torpedo control accordingly. Thus theposition of the electrical null point on each potentiometer at any particular time determines the control settingV that will be accomplished automatically.

To effect. a change in thek position of the electrical null point on any of the potentometers, hence to control` the torpedo, it is necessary only to adjust one ofV the variable attenuators 20| etc., (Fig. 13) to vary the amplitude of the transmitted signal for the channel involved. If an attenuator is shifted to increase the amplitude of a certain transmitted signal, the motor that is controlled (as described) by thatsignal will operate in such a direction as to move the contact of the potentiometer nearer to the ungrounded sideof that potentiometer; Conversely if the attenuator is readjust'e'd'toreduce the amplitude of the same transmitted signal, the motor will operate in the opposite direction.

Inl the preferred method therseveral signal generators 20|, V202, etc., are adjusted to have equal amplitudes of output, and the modulator 218 i's arranged to producev 100% modulation of the radio frequency carrier wave when each .attenuator isset for maximum amplitude of transmitted signal. The receiving system of Fig. 14 is so adjusted that the voltage across' each potentiometer is at every instant equal to the voltage that would exist simultaneously across any one o f the V loadresistors 24,6, v221, etc., if the corresponding attenuator were set 11' for maximum amplitude of transmitted signal.

Additional relays, such as relay 210 (Fig. 14) may be incorporated in one or more of the channels to accomplish other controlling functions of `an on-oi or stepping type. Furthermore, by employing selectively any one of several standard frequencies for the constant-amplitude reference signal, using relays in the position of relay 210 to switch the polarized relays to different sets of servo-motors and potentiometers for each case, it is possible to shift from one group of controls to another and thus to accomplish settings of many different controls in rapid succession.

In lieu of a fifth modulating frequency, two different carrier frequencies could be employed. In such a system one of the carrier waves would be modulated at constant level by all of the several control frequencies. The other carrier Wave would be modulated by the same frequencies, but each of these modulation components would be independently adjustable in amplitude and would be alterable in phase by increments of 180 with respect to the similar modulation component of the first mentioned carrier wave. After reception and filtering, each modulation frequency would be employed to operate a relay by means of a bucking circuit similar to those shown in Fig. 4a.

Equilibrium deflection of the control mechanism actuated by any given relay would thus be established by comparison of amplitudes of its particular modulation frequency on the two different carrier waves. Sense determination of the control movement from neutral position would be provided by a phasing network similar to the one disclosed in my pending application Serial No. 401,634, nled July 9, 1941, now Patent No. 2,338,732.

The principle of the double carrier Wave described above would possess the advantage of being extraordinarily difficult for an enemy to duplicate. For an enemy to gain control of the aerial torpedo, it would be necessary to know not only the two carrier frequencies being employed, but also the several modulating frequencies imposed upon those carriers, the proper correlation of each of the modulating frequencies with its particular operation on the torpedo, and the relative amplitudes and phases of the several modulations required for the desired results. It is possible that enemy action might discover one or more of these factors, but it is not reasonable to suppose that several of them could be measured and properly reproduced by an enemy during the extremely short period that would be available for the purpose.

Infrared my control is responsive to infrared rays comprises a pair.

of vertical thermocouples |2|, |22 (Fig. 4b) adapted to control the elevators, and a pair of horizontal thermocouples |23, |24 adapted to control the rudder or rudders. As shown in Fig. 3, these pairs of thermocouples may be mounted within housings |2|a., 23a, respectively located at the leading edges of wings 23. Each pair of thermocouples is connected into a channel that is identical with the channel of the other pair, so that it is necessary to explain the operation of only one channel. 'Ihermccouples 2|, |22 are connected to separate primary coils of an electro-mechanical transformer |25 (to be described) in which the mutual inductance of the primary coils with respect to a center-tapped secondary coil is variable in some periodic inanner by means of energy supplied from an external source. Y

The electro-mechanical transformerv |25 (Figs. 4a and 11) has two separate field windings energized by thermocouples |2 I, |22, and the phase relationship of these two field coils is maintained such that zero potential difference is induced in the secondary coil when the currents in the two thermocouples are equal. Associated with the electro-mechanical transformer is an alterhating current generator |26 having primary winding |21 which is energized by some constant current source, indicatedin the diagram as a battery |28, and which is coupled to a separate secondary winding |29 that is unrelated to the center-tapped secondary previously mentioned. This third primary |21 with its secondary |29 constitutes a separating alternating current generator, the sole function of which is to supply an alternating potential of constant amplitude having the same frequency as that produced across the center-tapped secondary, and maintaining a constant phase relationship to that across the center-tapped secondary. Whenever the radiation received by one of the thermocouples |2| |22 is more intense than that received by the other, the thermocouple currents are unequal, and an impulse or signal will then be transmitted to a conventional alternating current amplifier |30; but when the thermocouple currents are equal, no electrical energy reaches the input side of the amplifier.

The electro-mechanical transformer |25 converts an extremely small direct E. M. F. from the thermocouples to a higher E. M. F. (A. C.) that is led to the input side of the amplifier. Heretofore it has been proposed to transform a small direct E. M. F. as from a thermocouple to a higher alternating E. M. F. by connecting the thermocouple to the primary of a transformer and then moving said primary relative to a stationary secondary (connected to an amplifier) by power driven means. This principle is utilized in the transformer |25 to be described.

In Figs. 11 and 12, a directional radiation receiver is shown comprising a transformer housing |32 which encloses the electro-mechanical transformer |25 comprising a stationary center-tapped secondary coil |33, a pair of rotating primary coils |34, |35, shafts |36, |31, respectively for the rotating primary coils, like gears |38, |39, fixed on said shafts and meshing with driving gear |40 which is driven bymotor ||4|. Thus the primaries are in constant phase relationship to each other. Laminated pole pieces |42 increase the magnetic field as is known in the art of transformers. Vacuum thermocouples |2|, |22 are mounted on shafts |36, |31 respectively, and are electrically connected with respective primaries, as indicated in Fig. 4b. Shields |45, |46 are placed around the thermocouples in such a manner that each thermocouple can receive radiant energy only from points lying within a forward eld that is Wholly on the same side of the hori zonal axis of symmetry of the assembly. In this 13 way the current in primary coil |314v isa function of the total radiation received from Vthe area in front of the thermoccuples and below the horizontal plane of symmetry, while the current in primary coil is a function of the total radiation received from regions in front of the thermocouples and above this horizontal plane of symmetry. Shields |45, |46 or their equivalent are essential to prevent the thermccouples from being affected and perhaps rendered useless by the relatively intense infrared radiationI of the nearby power plant of the torpedo itself. The alternating current generator |26 is located in a housing |51 bolted to thev transformer housing and is directly driven by motor Mi. @Field coils M8, armature |59 and slip rings |56 are illustrated. Leads (not shown) are connected to the slip rings and conductaway an alternating current of constant amplitude, frequency and phase. `It

will be noted that the generator is driven at the same speed 'as the transformer primaries, `gears |38, |39 and Uli) being of equal size.

When the primary coils |34, |35 are rotated, alternating flux is induced in the laminated p'ole pieces |42. As these primary coils are so driven and. arranged as to producernagnetic fields which are at all times 180 apart in phase, the total ux in the core of the stationary secondary coil |33 is determined by the difference between the flux due toprimary coil |34 and that due to primary coil |35. It follows that the E. M. F. induced in the secondary coil |33 will be zero if the electric and magnetic Vportions of the transformer are symmetrical about its center and if -the currents in the two primaries are-equal. On

the other hand, any inequality in the primary currents will induce in the secondary an E. IVI. F. having a magnitude that is proportional to the difference between those currents and having a phase that depends upon which of the primaries is carrying the greater current. The primary currents are separately determined by the amounts of radiation received by the thermocouples 12|, |22 and therefore any inequality of radiation received by these thermocouples will produce an E. M. F. in the secondary coil, from the phase of which the sense of the radiation inequality can be determined Generator |25 is the source of phasing current used for this sense determination, and its i'leld coils |43 are excited by battery |22 shown. only in the wiring diagram, Fig. 4b.

By the described attachment of the thermocouples to the shafts of the rotating primary coils of the transformer, the necessity for slip rings, brushes and other movable electric contacts in the primary circuit is obviated, and the possible disturbing effects and losses due to variable contact potential and contact resistance are eliminated because a continuous electric circuit is maintained at all times. Rotation of the thermocouples is required under thisv system, but if the thermocouples are properly designed and are suitably mounted in vacuum, (not shown) this will not be' detrimental. Another valuable feature of the directional radiation receiver is the incorporation of iron in itsmag-l netic circuits in such a manner that no portion of this iron is in motion relative to the secondary coil. When used in this manner, the iron would produce comparatively high magnetic coupling between the .primary and vsecondary coilswithout subjecting the system to interfering effects when in the presence of constant magnetic fields.

When a signal or impulse from the thermo- 114 couples |2I, |22 reaches the center-tapped secondary |33, it is amplified by the amplifier |30 (Fig. 4b) and is then impressed uponY apush-pull circuit consisting of a dual-triode vacuum tube |5| and a center-tapped plate circuit |52 with load resistors |53, |54 and potentiometer |55. The plate voltage for the lvacuum tube |15| is supplied by battery |515 having one lead connected to thegadjustable contact |51 of potentiometer |55, while the other lead |58 is connected to the cathode circuit of the amplifier |30. The grid return circuit I59'of vacuum tube 15| is carried through the single secondary of transformer |25. The entire push-pull circuit is so adjusted as to be symmetrical about its electric center. one disclosed in my pending application Serial No. 401,634, filed July `9, 1941, its purpose being to provide a phasing method for determining which of the two thermocouples is receiving the greater incident energy at any instant. Thebalanced output circuit |52 of vacuum tube |5| is connected across the coils I'Ba of the polarized zero-center relay' |50 that controls servo-motor 31 through leads 49a, l29h to operate the'elevators. The operation of relay |60 is such that motor 31 is stationary at `all times when 'the currents in the vertically displaced thermo'couples |f2l, |22 are equal. However, if thermoc'ouple |21 receives greater radiant energy than A|22 and consequently passes a greater current "through primary coil |35, relay |60 closes in one particular direction. On lthe other hand if thermocouple |22 receives greater energythan thermoc'ouple |21, the phase of the signal passing' through ampliiier i3 is changed by 189 and the'relay closes in the opposite direction. Thus the motor which operates the elevators moves until the intensity of radiation on one thermocouple equals that on the other, at which time the Ytorpedo will be headed directly toward the source of infrared rays.

The horizontally displaced therinocouple's |23, |25 similarly operate through a transformer |6| and generator |62, amplifier |63, vacuum tube |65, resistors |65, |66, potentiometer |61, relay |68, and leadsl |69, |10 which connect with leads 58a, 591) to control the rudder-operating motor 35. Another lead Ima connects the armatures of both relays |613, |55, with the circuit-selecting switch 90. As long as 4equal intensities of radiation fall upon therrnocouples |23, |211', the rudder will not be moved, but any inequality in the intensity effects rudder movement such as will tend to turn the torpedo constantly toward-the source of radiation.

Detonation control the wings, fuselage and tail surfaces of the aerialV torpedo, the arrangement being such that a Vglancing blow struck any object will inevitably break the grid and cause detonation as will now be explained. A detonatorl |12 of'conventional construction is placed nearthe explosive charge 3'3l Thus the network is somewhat like theV and is .connected with a battery |13, having a lead I 14 connecting it with a relay |15. The latter is directly coupled with a relay |19 whose magnetic coil |16a is joined electrically (by a lead |11) with grid |1|. A safety switch |18, adapted to be closed just before the launching, and hence accessible from the exterior of the torpedo, is connected by a conductor |19 to relay |16 and is also coupled to the detonator by lead |80. When grid |1| is broken, solenoid |1611 can no longer hold the movable contactor |195 of relay |16 and said contactor opens to detonate the explosive charge. The detonator is also connected by a lead |8| with a detonator relay |82 which is under direct radio control of the remote operator. Detonator relay |82 has a magnetic coil |82a connected by lead |83 with the output side of rectifier 68 and by lead 13 with radio receiver 6|. As will be clear from the foregoing description, rectifier 68 delivers direct current to coil |82a when an impulse is passed by lter 62. This will cause movable contact |9213 to close which `in turn will detonate the charge. Thus at any moment in the flight of the torpedo it may be blown up at the will of an operator having knowledge of how to control the radio waves at the transmitting station (Fig. 13).

If the fuel supply is exhausted, the torpedo will cease its flight and start to fall out of control. To cause detonation as soon as theA engine slows up or stops, a centrifugal contactor |99, which is a single pole, single throw switch governed by a momentum-responsive device similar to a flyball governor, is connected in the detonator circuit. Leads |9| a, |9|b join the centrifugal contacter with relay |15 and another lead |92 connects it through relay |99 with the circuit selecting switch, as shown. A third wire |93 connects the centrifugal contactor |90 with detonator |12 through the safety switch |18. Centrifugal contactor closes the detonator circuit to detonate the charge whenever the engine speed falls below a certain gure. Thus after its flight the torpedo cannot return to the earth unexploded. This is of considerable importance not only because the torpedo is too dangerous to be allowed to fall anywhere on friendly territory, but also because it should not be permitted to fall unexploded on enemy territory, as the capture of an intact torpedo would aid the enemy by revealing the details of its construction. While the collision grid will inevitably cause destruction of the torpedo when it hits any ordinary object, the possibility of a fall into marshy ground or on cushioning material such as hay or straw should not be ignored.

Finally, detonation may be caused by relatively intense infrared rays. A pair of thermocouples |94, |95 sensitive to infrared rays are carried on the wings 23 near the tips thereof and are connected to an electromechanical transformer |95 similar to transformer |25 and hence unnecessary to describe. An amplifier |91 and a rectier I 98 receive the small impulses from the thermocouples |94, |95 and build them up to magnified direct current capable of energizing the coil |99a of a relay |99 connected by lead |92 to the detonating circuit including relay |16. It should be made clear that the impulses from the thermocouples |94, |95 are added to make an impulse which is a function of the total radiant energy received by both thermocouples; in this respect the infrared detonating system is different from the infrared directing system which operates by means of a difference in radiant energy received by the thermocouple pairs |2|, |22 or |23, |24. As the torpedo may narrowly miss its target and due to a lowered fuel supply may not again be maneuverable into a favorable attacking position, the infrared rays received upon close approach to the target should cause detonation, which will ordinarily effect disabling or destruction of enemy aircraft, since pieces of the torpedo will be blown in all directions.

Because the sun is the major source of infrared rays, infrared detonation will be prevented during daylight hours except underV unusual conditions as when seeking out an unseen enemy known to be operating nearby in a fog or heavy storm obscuring the sun. To cut out the action of relay |99, lead |92 has a switch 200 which may be opened by an operator before launching the torpedo. Switch 200 will be located so as to be easily reached from outside the torpedo. Where daylight operations only are to be conducted, the entire infrared detonating and directing systems may be removed or omitted from the torpedo, and all the other parts will operate exactly the same, except that the range may be increased materially if additional fuel is carried.

To prevent detonation until after the torpedo is launched and well on its course, a clock switch |84 is connected by leads |85, |86 with coil |15a of relay |15 and is also connected by leads |01, |88, |89 with the circuit-selecting switch. The clock switch controls relay |15 through relay |75 and prevents the closing of any of the above described detonating circuits until the clock has measured a certain time interval, for instance 20 seconds, from the moment of launching. With this arrangement, detonation will be impossible until 20 seconds have elapsed, after which the torpedo will be armed and may be detonated in any of the ways described above. To start the clock of the clock switch, a circuit may be closed by pulling out a plug 309 (Fig. 1'1) driven into a recess 3H) in a structural member 298 which is part of the torpedo. Said plug may have a central threaded bore 3|| receiving a screweye 3|2 which may be inserted by a member of the launching crew immediately before launching. Plug 309 spreads apart spring contacts 3|3 which tend to close. A cable 3|4 attached to the screweye may be anchored to a` part 286 (Fig. 15) of the launching mechanism to be described. As the torpedo leaves the launching mechanism under its own power, plug 399 will be jerked out, contacts 3|3 will meet and the clock will start running because of power derived from battery 3 I5. See Fig. 4a.

Torpedo launching Referring to Fig. 15, a cargo type airplane 215, only a part of which is shown, has conventional bomb-bay doors 216 hinged as at 211 and adapted to be opened or lowered by a hydraulic system not illustrated because well known. Fixed to the floor of the fuselage are rails 218 forming two or more tracks, and small cars 219, each carrying a torpedo, may move along said tracks to bring the torpedoes one at a time to a position over the launching opening. Clamps (not shown) may hold the cars and the torpedoes against movement until the time for launching. Each door 216 has one or more rails 280 fixed on its inner side and adapted to be alined with one of the rails 218 when the doors are closed, so that the tracks are continuous when the doors are closed. Exact alinement of the rails and locking of the doors maybe accomplished by slid'able pins 28|. on the ends of eachV rail 218 adjacent` the door opening, said slidablei. pins entering sockets 282 in the ends of rails 280. The cars 2l9withftheir`torpedoesjare rolled one at a time over therails and momentarily are supported "by thev doors. However, this extra'load on the A'doors' vis quickly removed by lowering a torpedoilaunching mechanismk having means' to connect'with and supportV a torpedo, as will now be'described.

-The torpedo-launching mechanism comprises a v'hydraulic cylinder Y'283 with Yits upper end hinged vas at 284 to the fuselage and havinga pistonrod" 285 pivotally connected with; and supporting a frameSE. Threep'arallelrods 28? forman. extension of frame 286 and'their lower ends are locked' with a .torpedo` at three :spaced points' as will be'described. With the torpedo rigidly held Vby the launching' `mechanismy'a starting motor 288 'is slidable' VVon ai stand V'ii towardfthetorpedo and its automatically disengaging clutch 2S@ is'coupled' with propeller. The doorsgmeanwhile, havev been opened and the torpedo with its propellers spinning will vbe quickly" lowered` by vthe hydraulic cylinder. To tilt each torpedo so that it will have a negative angle of attack? for f assured launching, one or morepairs oflinks -291' are pivotally connected toframe 289 attheir free endsand at their opposite endsfarepivoted as at 252' tothe fuselage. The-location ofthe' pivots and the lengths of links fidi are such that frafme 285? is turned through fa' smallfang'le as the torpedoes'are lowered.

Asshown-in Figs. l and 16, eachV torpedohas three 'hinged-covers Zeach closing an opening ZQS-in-V the outerV skin of the torpedo. Normally these covers remain `closed under-'spring pressure to `sa1 the openings tominimize drag. When onecof -thesupporting 1'ods9231 is'thrust against a' cover^295it willlfo'pen and permit -the rod to bemoveddown Vinto a socket Belin `the struc- -tural'ni'enb'er '2%. "Each rod contains two hyvdraulicj tubes `Afige-winchmay connect with a hydraulic i system V(notlv shown) similar to the door'operating system,-or' els`e"apart of Ythe latterjfand in either-case controlled by valves 'worked fromthe interior of the'airplane. Near the lower-'end each rod 281 has a cham-ber 300 in whieha hydraulic piston 3M recprocates. StopsjBZ on'eachsideA of the piston prevent it from-moving too far' either direction. A looking? pin 303, 'whichf'may 'belfiiiedv to 'piston 3 0 I will enter -arecess' in the structural member to lock the rod"to the torpeddwhenthepiston is in one position. However, when the piston is moved in the other direction the "pin`303 ywill move out of the recess to release the torpedo. When the rods slide Voutof the openings 296 'the covers will close automatically.

The described launching mechanism delivers the torpedoes one'at a time below theairplane, with ra negative angle of attack so thatthey will clear the airplane whenlaunched. Simultaneous releasing at all three points ofsuspension'is effected. Itwill be understood thatanumber of torpedoes may be stored on racks etc. inside the airplane at various points. If desired,'a smallcrane(not shown) may facilitate handling the torpedoesins'idethe airplane.

General discussion Y From 'they foregoing it will beclear thatA the described aerial torpedo, -within thelimits of its flight radiusjiscapable of outclimbingf and `enerny airplane from different directionsf overtaking 1 any ybombardment encargo-type planeV inthe world; "and if it is brought close to the targetjand exploded. itwill cause disablement or destruction of the target. Since g i he aerial torpedo;A is- `duite-I small and exceedingly fast, it' will 4present a verydiiiicultr y targetto gunners of airplanes ldefending againstj'attaclgs, and as it isgunmanned it cannot be stopped by killing `the pilot but only vbyl disablingsome-pf the controls oribyactual destruction of the ltorpedo at v.Somedistancefrom thedefending plane.

One serious limitation inherent inthe de sign of; lthea'e'rial torpedo isits short flying radius due ,to the small load of 'fuelwhich can be carried' inl the -v space available therefor is `this Adrawback cannotbe obviated withoutilowering` theperformance characteristis it is planned tot carry one or moreoijtheseflying torpedoes inthe bomb-bay' 'of a converted bombardment typev airplanejand toA release them when t h e enemy is sighted ori his proXin'iity'is indicated by yknown detection i devices. Then by radio impulses emanating; from the carrier aircraft or if desired Vfrom some` high-altitude observation plane or from a ground station, as the circumstances may dictate, the torpedo may-be Ydirected toward the enemy andwhen nearsuch aircraft may be-converted (at'thejwill'oftheremoteoperator) into an `autmnatic p ursniljlg weapon whichl will, overtake and destroythe targetV unless' stopped.; Obviously a --number of these vdevices may simultaneously'- aijtack` an lAs the" cost of the' aerial torpedoes will be a small fraction ofthe cost of v any yc o nventional military'jor naval @airplane and as no lossfof `iiying; personnel -is involved in'theirj use it' will be profitable" to send severalof 'these weapons against each enemy; aircraft sighted o rH fp ioked 'upf bythe 'usual-:signals It is anticipatedthat a swarm of several hundred such torpedoeswill scatter or destroy the heaviest armada of bombers itis` possible to put finthel airoYer ya givenl locality Yat'one time; without the 4l os s' y `of "any vlives in 'the defending forces. s incecarg'o V type 'airplanesI are capable' vof operationsup to 'to' 35,000 feet "or more,f it j is possible to release theseV torpedoes 'within striking distaneeo f the ceiling ofanyknownairplane, and at those rarelied laltitudesl tol destroyy enemy planes, ywhose pilots "are yinevitably encumbered 4and rendered inefficient by the usual high altitude equipment and conditions. v u

The described 'flying torpedo has .an armored, pointed nose V-22 not only to deflect bullets bnt also ."to' pierce the* structure of any airplane it may kbe sent against," thus; enhancing the `probabilityof complete"destruction* thereof.

vFor coastal fdefense "it 'has been proposed; yto transport small ghterrpianes'in dirigibles and release-theinv when "an" enemy is sighted,theregy tof d'estroythe ener'nyofar out at seabefore he 'can 'Treachfhisobjective. However," :'a's I*dirgibles have 'oniy ilimited "pay" `load 'capacity f and las fighter planes Weigh thousands of poundswhen 'fully 'f'u'el'ed; armed, armored, only 'azi few planes @cani 'bejaunchedfroma dirigible," V'and :re emo rkationY ofi theplanes iis exceedingly dimcult. and i in oerftainfweather conditions is fir'n possible. nce fighter planesfhavelimitedyring radii, fr any? such 1"' operations Ywell offshore 'mightf 'result Tin `'theio'ss' 'of all the 'fighters sur.- vivig anfengag'ement," together with" theirN personnel, lv tith l'the torpedoes of^`my invention; a large 'iun'riberv of which can be" 'carried on' ar dirigible, launching may take place rapidly. and once-the launchingV is completed, the dirigible is 'surrounded by a lswarm of protective fighters 'which-do not require re-embarkation and Which should hold at bay and inflict losses upon enemy forces until help arrives from the seacoast being defended. Thus the invention 'makes it possible for a single unescorted dirigible to defend itself by attacking enemy aircr'aft at a distance well out of range of any v-aerial vgun and without necessarily carrying any ammunition or guns, with no possibility of los- 'ing defending airplanes and their personnel. Only the-dirigible` itself is in danger but, it is believed, any attacking planes will be so busy 'defending themselves against the torpedoes that they will havelno opportunity to come close enough to strike at the dirigible. For remote controlof the torpedoes a dirigible offers the special advantages of better visibility and observation facilities, easier launching, more powerful radio transmitters, and slower speed.

The torpedoes may be especially adapted yto anti-submarine operations by omitting the detonator control which causes explosion upon striking any object and substituting a depth charge control 'such as has been in use since the first World War. If the submarine is detected running on the surface at night ork in a Yheavy fog, yet cannot be seen, several of the torpedoes may be launched and all will be automatically guided by infrared rays toward the submarine and will be detonated when they strike the submarine or the water surface nearby. For submarine defense obviously dirigibles offer important advantages; yet since large cargo type airplanes may carry several of the torpedoes, the employment of airplanes as mother ships for the torpedoes may often be preferred due to their greater speeds and higher ceilings. Y

-In the defense of airdromes or airflelds, the vtorpedoes of `myrinvention may be highly valuable, since they can be operated on a very small fuel supply and can be parked in small easily concealed sheds in the vicinity of the airdrome. Nofdefending pilotedair-plane need arise from the airdrome if advance warning `of an attack isreceived Such a defense would be particularly desirable von small strategic islands and `atisolated airdromes which must bedefended, ryet cannot be reached easily or manned with adequate defending personnel.

The theory may be advanced that any airplane Yor submarine defending against attack by the torpedoes of the invention could divert the course 'of a torpedo by tossing out a bright flare before the torpedo gets too close. Such a method of defense could only be successful if infrared directional control were employed, as at night. However, if such a tactic were resorted to, it would reveal theV enemys exact position and would almost certainly resultin.his'destruction by more orthodox methods, if not by the torpedoes of this invention; y

- The above discussion has been confined to .the Vuse of the aerial torpedoas a strictly defensive weapon and this isiits primary utility due to its limited range. '-However, in Ycertain types of offensive warfare, as for instance an attack on entrenched .troops where the points to be attacked canbe'kept under observation, the torpedoes may be. very useful especially as their radius of flight greatly exceeds the maximum rangev of the largest guns known in ordnance, and as their speed is so great that anti-aircraft defense would be practically helpless. It is believed that swarms ofthese torpedoes may be sent against troops, especially motorized troops on a highway, with demoralizing results. As steam locomotives are radiators of infrared rays on a huge scale, the torpedoes may also be used effectively in night attacks on enemy trains some distance behind the battle lines; and obviously power generating and steel plants will also make highly attractive targets because of their enormous radiation. When attacking aircraft from airplanes in flight having the described radio controls for directing the torpedoes, the control airplane may remain just out of range of fire of the targetplane and send in one or more of the torpedoes under remote control. Thus, even without employment of any infrared control or other target-seeking means, the torpedoes would constitute valuable weapons serving the same purpose as airborne artillery but lmaking available far greater effective radius of fire than is possible with conventional guns. Many other offensive and defensive actions may be made more effective by proper use of the torpedoes, as will be clear to military and naval experts.

It vmay be objected that if swarms of these torpedoes are let loose at night upon an invading air force some` of them will be guided bythe infrared rays of other torpedo power plants into collision and hence will be destroyed without damage to the enemy; However, by launching the torpedoes from widely separated points or from the same points at sufficiently spaced time in.- tervals, the overtaking of one torpedo by another will be impossible during their brief flying lives, and only chance will bring two torpedoes together when they reach the zone of enemy activity. Since the infrared rays of asingle airplane engine ofV 1200 to 2000 horsepower are far more intense than those emitted from a horsepower torpedo, it is much more likely that the torpedoes will be directed toward enemy planes than toward each other. However, if al collision between two of the torpedoes, both seeking the same target plane, does occur, it will likely occur near the target plane and the resultant explosion andthe destructive effects thereof will be greatly intensified by the fact that two torpedoes are involved.

j Having described one form of the invention, I desire it to beunderstood that many details may be varied or modified andA some may be omitted without departing from the invention, thescope of vwhich is defined in the appended claims.

' What is claimed is: Y K

,c l. A self-propelled pilotless aircraft havingya control system for automatically maintaining a predetermined flight pattern; a second control system for directing the aircraft constantly towarda source of radiant energy; a third control system responsive to operator-governed radio frequency signals;v said systems each lbeing selectively operable; and a fourth control system operated by radio waves under'the control of Van op#- .erator at a remote point and providing means to or vessel comprising, in combination, an operatorg "acogida -n-.iw.1,.- l .,1 i i: ci controlled transmitting system by Y,which two sig- .,nals.aretransmitted simultaneously on a single carrier Waveland in an amplitude ratio thaty may be variedat will by the operator; a receivinglys- -temcarried by the torpedo, etc. thatis capable of detecting and separating the two signals; a servof motork carried by the torpedo, etc.; Va circuit for theservo-motor which is coupled to the receiving system; an automatic comparator that causes the servo-motor to assume arposition for, each value .oamplitude ratioof the two signals; proportional .its distance from a pre-selectedmiddleposi- ,s Y -tionof rotation of said servo-motorand torpedo- Acarriedmeans. operated by the servorrnotorto vcontrol the movement or condition of the torpedo, etc. Y, Y. ,4.Theinvention according to claim, wherein the torpedo has several control means and servo motors andcircuits therefor, there being a servo` motor yforeach control means `of the torpedo` `each servo-motor circuit including a variable .voltage dividerv having a movable contact `op- ,Y erated by VYthe servo-motor in response., to the amplitude ratiouofvvthe two signals, the movable .l contact of thevvoltage divider being moved until yits circuit is. balanced about its electrical center; each control element moving synchronously with .the movable contact of the corresponding voltage dividenwr. c.

5. A flying torpedo comprising, in combination, a body so .formed and constructed Ythat it will ..fly, propulsive. means; guiding rmeans on the body; servofmotors for controlling theguiding .meanson the body; control circuits selectively energizing the servo-motors; automatic devices for selectively controlling the servo-motorsV and VAacting to hold the torpedo on a straight course unless disconnected; a radio-actuated circuitselecting. switch to which said automatic devices and controhcircuits .are connected; circuits responsiveto frequency modulated radio signal and connected to said control circuits and also con- A.nectedto the circuit-selecting switch; another servos-motor .for `.operating the circuit-selecting switch in one direction or the other to change the controlof the torpedo from automatic flight control to remoteior radio .wave control; the direc- .tion ofimovementrof. the circuit-selecting switch beingrdetermined by varying the amplitude ratio of twosignals transmitted from a remote point and under thercontrol of an operator. 6. The. invention accordingto claimr5, wherein ,theptorpedo l structure enclosesr an explosive ..cl'iz'a.rge,` a detonator for detonating said charge, a .-detonator relay thatupcn energization by radio l,signalactuates.said ,detonaton and a detonating .,rcircuit, and means controlled by received signal Varied by the remote operator to close the relay to detonatethe charge. Y,

f7.. The invention according to claim 5, wherein thereisa system of/controls including a plurality VLof infra-redsensitive elements distributed on the torpedo, said controls being connected with the guiding means and actuatedby variation in in- '.tensities of infrared rays falling ondifferent areas 4of thetorpedo to cause the v torpedo to y toward A.the source ofV the infrared rays; said system being connected .electrically with the Vcircuit-selecting switch and being vcut in or .cut out at the will of the .remote operator controlling at least one radio carrier wave upon which are impressed a plurality. f meduletiensf. .7,

8. A flying: torpedo havinga body sc .formed v .target to whichit has been carried by thecooileration of the rudderand elevator-controllin circuits. Y

`gelati.L enStriieted,thatA it, wlfly, a redden ,e1-rf.

evators and ailerons on the body; a reversible andA operating at...e1l. tiriiesY independently uef ell other controls; radio wave-resp''onsive` circuits for eperetirie themeters. fei'ihe .rudder enleleveiers independently. from. e remote peinti-eutemetie means including circuits to controlv the flight of the torpedo te e, eulesientiellyfstreieht -eeiireei v e circuit-selectingswitch ,eenneeied inte the lest named circuits and also connected into. the radio Aven/.efreepeneive eireiirs: and, e radio-Waveresponsive circuit to change the controlA of` i the torpedo frompurely automatic toremote control and back again at the will of the operator,

c 9.*A flying torpedo having ebedvee formed end Shaped that itwill ily. end e selffeentelned power plant, said body also. havingan explosive charge; a detonator yin a circuit; another circuit,

including means ,responsive-to a change in the ratio between the, modulations impressed upon at least one radiowave, .electricallycoupled .to

the detonator circuit andadapted to control the detonator circuit to detonate the charge; stillanother circuit including multiple therrnccouple means distributed Aonthe torpedo in diverse locations responsive to infrared waves vand means for amplifying, end deteetiiie the minute-.thermecouple current; `said last-named circuit being -eleeirieelly eeiipled., te the deieneiei `efilit.. i0 cause detonation when the infrared rays reach acertain intensity.

10. A flying torpedo comprising, in combination.

'a' body having propulsive` means and guiding means including a rudder, elevators and ailerons;

the cooperation of whichwill enable the torpedo to banl; while turning, 'automatic control circuits including tworeversible servo-motors to control the guiding means tohold the torpedo normally in straightiiight; and remote control means comprisineen antennae redie reeeiveret leest two band pass lters atleast two amplifiers, at least two rectifiers, two potentiometers and at lleast two relays; each servo-motor being electrically connected to one of said relays and being mechanically connected to the movable contact of one of said potentiometers; the parts being so cooperatively constructed, connected and arranged that control resulting in the reception of signal and conversion thereof into mechanicalA operation of the controls is effected yby a remoteoperator by varying individually the percentages of modulation on the carrier Wave dueto two single ,modulating frequencies of suitable value to be passed by the respective filters.v

11. The invention according to claim lowherein there is a fourth radio-responsive .control circuit having a band pass filtercoupled to said receiver, an amplifier, a rectier, a potentiometer and a vrelay allcoupled to the band pass filter; an explosive charge in the body; a de tonatorvv and circuit therefor; the detonatorcircuit being electrically connected with the fourth circuit so that by varying the percentage o f `modulation on the carrier wave' due to one modulated frequency the detonator circuit will be sufficiently excited to detonatethe charge at a position adjacent the 1 1 eeeirellableilviiia teriieiofeelnprisiie, in 15 combination, a body so formed and shaped that it will iiy; a power planton the body for driving kthe same; controls on lthe body-to'cause the `torpedo tov turn, bank, -dive or climb; a system responsive to Voperator-controlled radio Waves,

"said system being carried on'the body-and ef- "fecting control of the-flight o-the torpedo v'and having r'an antenna forreceiving vlradio signals governing the flight course of the torpedo, a radio "receiver coupled to the antenna, 'a band pass filter coupled to the receiver, an amplifier-coupled to the band'pass iilter; a rectifier connected to the amplifier; a potentiometer connected to the rectifier; and a` polarized relay electrically conrectifier, so that any signal appearing in the output of the band pass lter will tend to actuate the relay in one particular direction; another circuit leading oi fromthe radio receiver and connected to the relay and giving a direct potential having an amplitude that is proportional to the intensity -of the radio carrier wave received by the antenna and passed through said receiver, this potential being applied to the relay in such a manner as to oppose thepotential'from the rectifier to the relay, so that for anypa'rticular setting of the potentiometer, a given percentage of modulation on the frequency of the filter causing zero current through the relay; the relay closing in one `direction if `the modulating signal on the frequency to which the lter responds is increased in amplitude while the carrier Wave remains unchanged, the relay closing in the other direction if Ythe signal from the filter is reduced in amfplitude; and a reversible servo-motor electrically connected with the relay and with a source of electricity and mechanically connected with one of the controls of the torpedo to operate said control in opposite directions.

13. The invention according to claim 12, wherein the servo-motor has mechanical connections with the movable contact of the potentiometer to move the same; the direction of operation of the contact being such that the system always seeks `its equilibrium position in the absence of modulating signal. Y

14. An aerial torpedo comprising a fuselage,

' propelling means, a tail vstructure and wings; an

explosive charge in the fuselage; a detonator and a circuit therefor including a source of electricity; and a grid consisting of a fine Wire strung throughout the fuselage, tail structure and wings; said grid being electrically connected to the detonating circuit, and a relay also in said circuit which is electrically `connected to the grid so that-the relay closes when the grid is broken at any point, thereby to close the detonator circuit tc detonate the explosive.

` 15. An aerial torpedo `having abody capable of sustained guided night and carrying an explosive charge and a detonator; a detonating circuit including a sourceof electricity, a relay, a rectifier,

- an amplifier, a thermocouple sensitive to infrared rays', and the detonator, all coupled together; said relay closing when subjected to amplified impulses generated by the thermocouple responsive to infrared rays, and detonating the charge.

- '16. The invention according to claim 15, wherein there is a circuit-selecting switch on the torpedo; a servo-motor for operating the switch; a motor control circuit controlled by frequency i propelling means, and containing an explosive modulation by an operator at a remote point; and a circuit connecting the circuit-selecting switch and said relay so that the remote operator. may make the relay operative or inoperative bycontrolofradio. signals' to vary appropriately the amplitude thereof to accomplish the result de- 17; YAn aerial torpedo comprising a body having 'flight-sustaining means, guiding meansand charge; means controlled by differences in intensities of infrared rays falling the torpedo and acting automatically to guide the torpedo constantlyV toward .the source of such rays; a .detonator for detonating the explosive charge; and means controlled by infrared rays and automatically operating upon a predetermined material increase in such rays to detonate the explosive charge.

18. Anl aerial torpedo comprising a body having flight-sustaining means, guiding means, and propelling means; a charge of explosive and a1 detonator in :the body; and means carried on the body and controlled by infrared rays and acting automatically upon a very great increase in such rays to detonate the explosive charge; said means comprising a plurality of thermocouples, av detv onating circuit controlled by the thermocouples,

a source of electricity for energizing said circuit; and means to shield the thermocouples from the radiant energy of the propelling means.

'19. An aerial torpedo having the characteristicsV of an airplane, with Wings, rudder and elevators; a heat radiating engine propelling the torpedo; two pairs of thermocouples, each pair being mounted on the leading edge of a wing; electro-mechanical means including a group of electric circuits interposed between one pair of thermocouples and the rudder and acting responsive to differences in intensities of infrared rays received by the thermocouples to turn the torpedo in the direction whence rays of the most intensity emanate; similar electro-mechanical means interposed between the other pair of thermocouples and the elevators and actinginthe same manner to direct the torpedo toward the most intense rays; a group of electric wave lters included as an element common to all of said circuits; an explosive charge in the torpedo; and an electric circuit for detonating the same, said circuit including one lterof the said group of filters.

20. The invention according to claim 19, wherein means are provided to shield each thermocouple of each pair from one-half of the area `in front of the torpedo so as to be sensitive only to infrared rays either to the right or left ofthe vertical plane of symmetry,ror above or below the horizontal plane of symmetry, as the case may be.

2l. The invention according to claim 19, Wherein the wing tips carry a third pair of thermocouples and a circuit connects this third pair of thermocouples with the detonating means; the parts being so constructed, connected and arranged that When infrared rays of a suitable high intensity fall upon the Wing tip thermocouples, or either of them, the charge will be detonated.-v

22. Anv aerial self-propelled torpedo having means for controlling the direction of flight; automatic means in the torpedo for operating `the iiight controls to maintain iiight in a straight path; radio Wave-controlled means for disconnecting said automatic means and for taking over iiight control; an explosive charge; detonating means; means to effect detonaton upon 

